The present invention relates to catheters for insertion into the body of a patient, and to compositions useful for producing such catheters. More particularly, the invention relates to such catheters, for example, linear everting balloon catheters, which are relatively easy to produce, relatively easy to insert, and are effective when inserted into the patient's body.
Medical catheters often must pass through tortuous paths in a patient's body before arriving at the desired location. Much difficulty, and discomfort and even danger to the patient, is frequently encountered in manipulating such catheters in the patient's body. The presence of guidewires does not resolve this problem. For example, previous everting balloon catheters, e.g., useful in angioplasty procedures, tend to perform in a less than desired manner in terms of tracking along a guidewire. The distal end or tip of the catheter body is too stiff and the inverted balloon catheter system does not allow easy guidewire movement.
Another problem which arises in using certain catheters is the need to know quite precisely where the catheter is in the patient's body. Conventional fluoroscopy procedures have teen used to visualize catheters in the body. These catheters have bands of heavy, radioopaque metal at or near the distal end of the catheter to facilitate such visualization. Such radioopaque metal bands do present certain difficulties. For example, such bands involve an additional manufacturing step. Also, if the bands are away from the distal tip of the catheter body, the precise location of the distal tip is not readily apparent On the other hand, if the bands are located at the distal tip of the catheter body, they may interfere with the functioning of the catheter.